Recently, it was reported in the prestigious New England Journal of Medicine that the health benefits of nuts were such that eating a handful (about 30g) daily could reduce the risk of death from any cause (known as "all-cause mortality") by 20pc compared with not eating nuts.
This builds on existing data that suggests that daily nut consumption in small amounts reduces the risk of certain cancers, cardiovascular disease and type 2 diabetes.
It is timely, then, to explore exactly which nuts we should choose to eat and provide some practical advice about how they can be included in the diet.
WHAT ARE NUTS?
'Nuts' is a broad food category of what are very often actually seeds or dried fruit. For example, almonds, pistachios and pine nuts are technically seeds, whereas peanuts and cashews are seeds of legumes, and therefore not nuts at all! Hazelnuts, pecans and walnuts are 'true' nuts because they are hard-shelled and don't open to spread seeds.
Nuts, in the broadest sense, are high in calories, rich in essential fats, protein, vitamins, minerals and antioxidants, which, by virtue of them being energy and nutrient-dense, makes them an excellent food choice.
However, like most foods, there are 'good' and 'bad' nut choices.
Almonds are low in calories relative to other nuts, are a good source of fibre and have more calcium than any other nut. They are also high in vitamin E, which helps to reduce inflammation and improves the condition of skin.
Choose whole almonds with the skin intact and not bleached or flaked almonds (where beneficial flavanoids have been removed).
Pecans are a good source of protein and fibre. They contain zinc, which helps the body generate testosterone.
Pecans are a rich source of plant (or phyto-) sterols, which have been found to be effective at lowering LDL cholesterol levels. They are also an excellent source of antioxidants that can help to reduce inflammation in the body.
Walnuts are rich in the omega-3 fatty acid alpha-linolenic acid (ALA). Omega-3 fats have anti-inflammatory properties and help reduce the risk of cardiovascular diseases.
Studies have found that walnuts have many benefits, such as lowering cholesterol, improving endothelial function, protecting against diabetes and reducing inflammation.
Brazil nuts are rich in the vitamin thiamine (B1), magnesium, zinc and calcium and selenium, which studies show significantly reduces the chance of developing prostate cancer. Brazil nuts also contain ALA.
Cashews contribute a good level of protein and are a useful source of minerals like magnesium, iron and zinc. They have a nice natural sweetness that makes them an excellent snack for helping to manage sweet or sugar cravings.
Pistachios are rich in the same phytosterols that have been found to help lower LDL cholesterol as well as heart-healthy monounsaturated fats.
Pistachios are the only nut to contain reasonable levels of lutein and zeaxanthin, antioxidants that play an important role in protecting eye health. They are also a decent source of potassium and fibre, but you should try to find the unsalted variety.
Hazelnuts are rich in essential fats and are a source of calcium, important for healthy bones, teeth and intracellular ion balance. They can be used to make milk if you want a dairy-free option.
Macadamias have a higher percentage of heart-healthy monounsaturated fat than any other nut, seed or vegetable. They also contain phosphorus, potassium, magnesium and calcium, essential to cell, nerve and muscle functioning.
Unsalted, whole peanuts do contain some health-benefiting nutrients such as oleic acid and folic acid.
On the downside, peanuts are very high in omega-6 fat, which although essential for health is known to be pro-inflammatory when consumed in excess.
In addition to the high omega-6 content, peanuts are not as rich in essential nutrients compared with other varieties and therefore should not be a significant contributor to your nut intake.
Moreover, peanuts are one of the most common food allergens and thus must be avoided by anybody with even a mild nut allergy.
Nut butters are a great option for snacks – they taste great with raw fruit and vegetables such as apples, carrots or celery. When choosing a nut butter, look for spreads with only the nuts (and seeds) as ingredients on the label.
There are many varieties that contain added processed seed and nut oils to enhance the shelf life and spreadability. Sugar and salt are other common ingredients that are used to enhance the taste.
NUTS TO AVOID
When it comes to choosing the right nut options, the simple thing to remember is to choose nuts with no additives such as sugar, sweeteners, chocolate, yogurt, vegetable oils, flavour enhancers or salt. Learn to appreciate nuts that have not been processed in any way.
WHAT ABOUT THE FAT CONTENT?
Nuts are high in fat, but what is key is that some of these fats are in the form of "essential" fats such as omega-3 and omega-6 that are important for optimum health.
Additionally, nuts are rich in mono- and polyunsaturated fats, which again when consumed in the right proportions can contribute to improvements in metabolic health.
If we instead think about energy (calorie) intake, the reality is that when eaten in sensible quantities, nuts are certainly not fattening. In fact, research has shown that nuts can help people to reduce their body fat and control their weight.
ADDING NUTS TO YOUR DIET
Nuts can be added to your own homemade muesli or granola, mixed with natural yogurt, eaten with fruit and be used in multiple savoury recipes, salads and, of course, to make desserts.
Many of our @FoodFlicker dessert recipes include some type of nuts that, when combined with dark chocolate, are always a great hit. Check out @FoodFlicker this weekend for a healthy nut and seed dessert recipe.
Daniel Davey BSc MSc, CSCS, NEHS is a performance nutritionist